Automatic stoker for furnaces



Feb 12 1924. 1,483,785 J. T. cuLLEN. JR

AUTOMATIC STOKER FOR FURNACES I Filed Sept. 26. 1921 3 Sheets-Sheet 1 8vwento-z Feb. 12 1924. 1,483,785 J. T. CULLEN, JR

AUTOMATIC STOKER FOR FURNACES Filed Sept. 26. 1921 3 Sheets-Sheet 5 E1?vuvvuvvvuvvuvvuvv V avwenlroz Patented Feb. 12, 1924.

U N 1' 'iEAI JQHN- '1. QULLEN, an, or; CLINTON, town.

AUTOIJEAI'IC. STOKEI'L- FURNACES.

Application filed September 26,, 1921.

To, all; whom it may oo'neemx Be it knownthat 1, Joan T. Gunman, J12, a.citizen. of the United: States, residing at Clinton, in the county ofClinton and State of; lo a, have invented new and useful Inn.- pnovenents in. Automatic Stoker's for. Furnaces ofwhich the following is. a,specification. I

This invention. relates, to automaticv stole ens -for furnaces, and hasfor one, of its objocts the provision of a Stoker the operation of whichis responsive to temperature on pressure, conditions within the fnnnace.

Another, object of theinvention is theprovision of a Stoker in which themechanical elements are actuated through. the agency of;- fluid,pressure which is controlled by a. physical condition. in the furnacedependent upon the state of; the fire.

Another object oft-he invention is to. pro.- vide an automatic. stolrerin which two sets of rocking gratev bars, one set of which is arrangedin alternate relation to the other successively operated by the movementin one. direction. of a fluid pressure actuated plunger, the admissionof fluid to said plunger being controlled by variation in thetemperatureof the furnace fire.

A furthenohjectof the invention is to proride in an automatic stoker ofth class described a spring for returning the grate bars immediatelyafter they have been rocked by the fluid pressure actuated means, saidgrate. bars being, in addition, presently returnable by the fluidpressure means in the event of breakage of the. spring means, so

asto aroid; damage tothe grate barsby leaving them projected into thefire.

A still further obj cot of the invention is to v provide a Stoker inwhich the elements opgwating the grate bars are moved by a fluidpressure actuated plunger, the admission of fluid to which is controlledby a valve, automatically responsive to. a physical condition withinthe'furnace resulting from the. state of the fire.

And, in the embodiment specifically disclosed in the drawings in whichthe, furnace isproyided with a boiler and the. fluid pressure foroperating. the phnager is derived from water in a pressure main. anobject of the invention is to connect the bleed passage which isprovided for the pressure side of the distributing: valve to the boilerand to associate therewith means for. controlling the How through saidbleed passage as to Serial No. 593,307.

feed; to the boiler... water. at av rate suificient to ma nta n, a.constant level therein.

For the attainment of. theseends and the accomplishment. of. other new.and useful,

objects as will appear, the, invention conlsists in. the features of.novelty in, the. con.- struction, combination air arrangement Off theseveral, parts generally. shown, inthe ac-l companying drawings and,described: in the specification, but more particularly pointed out in.the. appended claims.

In the, drawings Figure 1 is a side elevation ofa furnace equipped: withmy automaticstoker. i J: Eigure. 2 is a front elevation. of; the sarnefurnace.

ljigureBisa plan view ofthe grate. Figure 4 is a slide elevation thegrate shown in Figure V M Figure 5 is a. longitudinal. view in detail.of one of the. grate bars. V

Figure. 6 is a' detail: View showing the distributing valve and thebleed passages lea-d.- ing to the boiler. 1 i V i In. the drawings thefurnace is represented by. the numeral. 1 and is proyided with the frontWall 2. which forms the support for one end of a boiler 3', y In thelower, part of the. furnace beneath theboiler. is the grate 4 whichinclines rearward ly from. the fire door 5 ofthe furnace to the ashplate 6 which is. preferably formed of-iiia sonry and is adjacent thevash-pith Fuel is fedatthe fire door 5 and an ash-door. is. located atthe bottom of the front Wall of the furnace below the grate. On theexterior of the front wall 2 of the furnace. is arranged the majorportion of the mechanism by which the. grate bars are automaticallyoperated.

Referring more in detail to. the parts the grate. comprises the inclinedside members, 8 spaced apart the width of the grate...bars and eachprovided in its upper surface. with semi-cylindrical bearing. recesses9. for. the reception of the similarly. shaped l. ugs.10. on theopposite ends. of the. grate bars. Each of the grate bars consists of acasting hav; ing a flat upper surface 11 constructed with spaced barsand a cylindrical longitudinal apron 12, concave on its rearsurfaceextendi through an arc of substantially. 90?. Said; casting is;provided at its opposite ends with projecting semi-cylindrical bearingtrunnions. the upper. surface of each of which is in the plane of the.upper surface of the grate bar, said trunnionsprojecting rearwardly ofsaid grate bars so that the axial line through said trunnions is inalignment with the rear edge of the grate bar. Secured to the lower edgeof the apron 12 and preferably formed integral therewith is the lever 13provided near its lower end with a slot 16 for connection with the drawbar 14 presently to be described. There are two draw bars, 14 and 14respectively one on each side of the grate and the grate bars areconnected therewith alternately in gangs so that every alternate gratebar is connected to the draw bar on one side and the remaining gratebars to the draw-j bar on the other side. The connection of each gratebar with its respective draw bar is by means of a pin 15 secured to saiddraw bar and projecting through the slot 16.

In the operation of the device the bars 14 are successively drawn towardthe front of the furnace. This causes one set of alternately arrangedgrate bars to rise to the dotted line position shown in Figure 1 dumpingthe coals which they support upon the alternate bars, which at this timelie flat. The first set of bars then return to position and the otherset rise dumping the fire which they carry upon the bars of the firstset which now lie flat. In this way the fire is advanced slowly towardthe rear of the grate and by the time the last grate bar is reachedcombustion is practically at an end and the ashes are deposited upon theash-plate 6 from which they are raked at appropriate intervals into theash-pit 7. The aprons 12 prevent the fire falling between the grate barswhen they are tilted and also keep the coals and clinkers from lodgingtherebetween.

The mechanism for operating the draw bars 14 and 14 comprise.bell-cranklevers 17 and 17 one for each bar as clearly shown in Figure 2. Thebell-crank levers are pivoted at 18 and 18, each to a bracket 19 securedto the front wall of the furnace. One arm of each bell-crank isconnected to the outer end of the corresponding draw bar by a pin 20sliding in the slot 21 in the arm of said bell-crank. Springs 22 and 22return the bell-cranks and the draw bars 14 and 14' respectivelyconnected; thereto, to normal position after they have been actuated anda spring 23 between the front wall of the furnace and the end of eachdraw bar 14 prevents undue shock or ar in returning the grate bars tonormal position.

Secured to the front of the furnace wall at distance above the brackets19 are the pairs of brackets 24 and 25. In each pair of brackets isjournalled a rock shaft, one of which, designated by the numeral 26 isprovided near its end with an arm 27 carry 'ing at its end a pivotedshackle 23 to which is connected at one end a rod 29 the other end ofwhich makes connection by means of a shackle 30 with the free arm of thebellcrank lever 17. A turnbuckle 31 intermediate the ends of the rod 29permits the length of the latter to be adjusted.

The rock shaft 32 which is journalled in the pair of brackets 25 issimilarly provided at its outer end with an arm 33 which is connected tothe free arm of the bell-crank 17 by means of a sequence of mechanismsimilar to that described in connection with the rock shaft Between thebrackets of each pair the rock shafts 26 and 32 are respectivelyprovided with the rigidly attached dogs 34 and 35. These dogs are ofequal length and the outer end or nose of each projects into the path ofa U-trip 36 carried at the outer end of a vertically reciprocatingplunger rod 37 which passes through a stuffing box 38 into a cylinder 39where it is secured to the piston 40. One end of each rock shaft isprovided with a hand crank to permit manual operation of the stoker whendesired.

The piston 40 is arranged to reciprocate in the cylinder and when on itsupward stroke the U-trip 36 engages first the nose of the dog 34 raisings id dog and partially rotating the rock shaft 26 which movementelevates the arm 27 and rotates the bell-crank l7 pulling out the drawbar 14 and operating one set of grate bars. As the U-trip continuesupward the nose of the dog 34 escapes therefrom and the parts, includingthe grate bars which have just been elevated, are returned to normalposition by the spring 22. The U-trip, continuing its upward movementengages the nose of the dog 35 raising the latter and operating the rockshaft 32 lifting the arm 33 which pulls up the bell crank 17 raising theother alternate set of grate bars which are returned to normal positionin a manner similar to that of the first set of grate bars, when thenose of the dog 35 has slipped from engagement 'ith the U-trip 36.

The piston 40 is actuated by fluid pressure taken from any convenientsource such as steam within the boiler, water from a town pressure mainor oil from a closed pressure circulation system. in the embodiment heredisclosed the pressure is derived from water taken from the main 42. Atwo way distributing valve 43 is provided by means of which each side ofthe piston 40 is alternately put in communication with the water mainand subjected to the pressure of the fluid therein.

This valve is shown in detail in Figure 6 in which 44 is the casing ofthe valve connected, at 90 intervals with the supply conduit 42, thepipe 61 leading to the top of the cylinder 39, the pipe 45 leading tothe bottom of said cylinder and an exhaust conduit 46 for drainingeither side of said cylinder when it is relieved from pressure. A barrelvalve 4? operates in this casing and is cut away on opposite sides:forming passages 48, and 49.

which by turning said valvemay place the, top or bottonrof the cylinder1ncommun1ca tion with the water main! and: at thesame 1 time place theotherend, of the cylinder; in,

communication with the exhaust conduit; As pressure isiusuallymaintained for a considerable intenvalrof: time in: eitheu end of thecylinder during the operation of the, de-

vice,bleed passages 56 are provided. in the valve l3 to prevent leakageof fluid past the piston 40.

The operating handle 50-ofthe valve l3, is connectedthrough a link 51,,and lever52 with a pressurediaphragm 5st incommunication with theboiler. A sliding weight 55 arranged on one end of the lever 52determines at what pressure the diaphragm will The valve and itsactuating parts;

- the lower sideof the cylinderin co1ninunication; with thew-ater mainl2 until the pressure of steam within theboiler has reached apredetermined degree at which time the diaphragm 54c will cause thevalve 4L3 to turn putting, the upper end of the cylinder incommunication with the source of fluid pres sure and the lower end incommunication with the exhaust conduit 46. This will cause the descentof the U-trip which will freely pass the noses of the dogs 34 and 35since the latter will yield against the pres sure of the spring 22. TheU-trip will then remain in its lowest position until cooling of the fireso lowers the pressure of the steam in the boiler as to cause the valve43 to be again turned to admit fluid pressure to the lower end of thecylinder when the automatic stolzing of the fire will be repeated.

Should for any reason either of the springs 22 or 22 become broken ordisconnccted thedogs 3401- 35 will remain extended in the path of theU-trip 86 which will on its descent, impelled by the pressure on theupper side of the piston positively depress said dogs and through them,push the grate which may be done by uniting them into a single conduit57 communicating, directly with the boiler. By arranging the bleedpassagesQO apart asshown, oneis' alwaysin; communication with apart 0ftthe1valvewhiolnis under the-pressure of the water in, tlie mami 42. Byproviding.- an appropriate pass valve 58- and a cheek valve 59 in theconduit 57 the flow of water through said;

bleed passage may be-so adjusted asto compensate for the lossof' waterin; the boiler through evaporation and other. causes and maintain a.constant level of water therein.

It is obviousthat various changes may be made in: theidetails ofconstruction without departing: from the invention and: it is thereforeto be understood that this invention is not to belimited to the-specificconstruction shown and describech,

Having; described my invention what I claim as new and desire to secureby Letters in one direction for operating said grate and means forreturning said bars immediately to; normal position after operation, andmeans responsive to the, pressure in said boiler for controlling theconnection of said fluid pressure system to, said operating means.

3. In combination with a furnace, an automatic stoker thereforcomprising a grate, sets of rocking bars for said grate, the bars ofoneset being arranged alternately to the bars of another set, operatingmeans for each set of bars, each operating means, being constructed tosimultaneously operate the bars of its set and a fluid pressure devicehaving a plunger and means successively engaged by said plunger whenmoving in one direction to sequentially rock the sets of grate bars.

4. An automatic stoker comprising sets of alternately arranged gratebars, means for operating said sets of bars comprising a rock shaft foreach set operatively connected thereto, dog on each rock shaft, acylinder, a plunger within said cylinder, trip means carried by saidpluinger, said dogs extending into the path, of said trip means, saiddogs being successively engageable by said trip means when the plungeris moved in one directionand yieldingly movable from the path of saidtripmeans when the plunger moves in the other direction.

5. An automatically controlled stoker comprising sets of alternatelyarranged grate bars, means for operating said sets of bars comprising arock shaft for each set operatively connected thereto, a dog on eachrock shaft, a fluid pressure actuatedplunger, a spring for each dognormally holding said dog in grate closing position, a spring normallymaintaining said dogs in the path of said plunger, said dogs beingsuccessively operated by said plunger when moving in one direction torotate said rock shafts and yieldably movable from the path of saidplunger topermit passage of the latter when moving in the otherdirection.

6. An automatic stoker comprising sets of alternately arranged gratebars, a rock shaft for each set of grate bars for operating the same, adog secured to each rock shaft, a fluid pressure cylinder, a plunger insaid cylinder, means reciprocable with said plunger for successivelyactuating said dogs to operate the sets of grate bars, means forreturning said sets at once to normal position after said actuation, asource of fluid pressure, and means for putting said source of fluidpressure into communication with either end of said cylinder.

7. An automatic stoker comprising sets of alternately arranged gratebars, a rock shaft for each set of grate bars for operating the same, adog secured to each rock shaft, a fluid pressure cylinder, a plunger insaid cylinder, means reciprocable with said plunger for successivelyactuating said dogs to operate the sets of grate bars, means forreturning said sets at once to normal position after said actuation, asource of fluid pressure, and a two way valve for putting said source offluid pressure into communication with either end of said cylinder.

8. In a furnace, an. automatic stoker there for comprising sets ofalternately arranged grate bars, a rock shaft, for each set of gratebars, for operating the same, a dog secured to each rock shaft, a fluidpressure cylinder, a plunger in said cylinder, means movable with saidplunger and successively engageable with said dogs for operating saidrock shafts. a source of fluid pressure, means for putting said sourceof fluid pressure into communication with either end of said cylinder,said means being responsive to a physical condition within said furnacedependent upon the state of the fire.

9. In a furnace, an automatic stoker therefor comprising sets ofalternately arranged grate bars, a rock shaft, for each set of gratebars, for operating the same, a dog secured to each rock shaft, a fluidpressure cylinder, a plunger in said cylinder, means movable with saidplunger and successively engageable with said dogs for operating saidrock shafts, a source of fluid pressure, a valve for putting said sourceof fluid pressure into communication with either end of carried by saidplunger successively engageable with said dogs for operating said rockshafts, a source of fluid pressure, means for putting said source offluid pressure into communication with either end of said cylinder, andmeans responsive to pressure within said boiler for controlling saidmeans.

11. In combination a furnace, a boiler associated therewith, anautomatic stoker therefor comprising sets of alternately arranged gratebars, means for operating said sets of bars comprising a rock shaft foreach set, a dog rigidly secured'to each rock shaft, a fluid pressurecylinder, a plunger in said cylinder, means carried by said plungersuccessively engageable with said dogs for operating said rock shafts, asource of fluid pressure, a valve for putting said source of fluidpressure into communication with either end of said cylinder, and meansresponsive to pressure within said boiler for controlling said valve.

12. An automatic stoker comprising sets of alternately arranged gratebars, means for operating said sets of bars comprising a rock shaft foreach set operatively connected thereto, a dog on each rock shaft, afluid pressure cylinder, a plunger working in said cylinder, meansmoving with said plunger and successively engageable with said dogs foroperating said rock shafts, a valve, a source of fluid pressurecommunicating therewith, conduits leading from said valve communicatingwith the opposite ends of said cylinder, an exhaust conduitcommunicating with said valve and means for operating said valve to puteither end of said cylinder into communication with the source of fluidpressure and the opposite end into communication with said exhaustconduit.

13. In combination a furnace, a boiler associated therewith, anautomatic stoker therefor comp-rising sets of alternately arranged gratebars, means for operating said sets of bars comprising a rock shaft foreach set operatively connected thereto, a dog on each rock shaft, afluid pressure cylinder, a plunger working in said cylinder, meansmoving with said plunger and successively engageable with said dogs foroperating said rock shafts, a valve, a source of fluid pressurecommunicating therewith, conduits leading from said valve communicatingwith the opposite ends of said cylinder, an exhaust conduitcommunicating with said valve and means responsive to the pressure insaid boiler for operating said valve to put either end of said cylinderinto communication with the source of fluid pressure and the oppositeend into communication with said exhaust conduit.

14. In combination a furnace, a boiler associated therewith, anautomatic stoker therefor comprising sets of alternately arranged gratebars, means for operating said sets of bars comprising a rock shaft foreach set operatively connected thereto, a dog on each rock shaft, afluid pressure cylinder, a plunger Working in said cylinder means movingwith said plunger and successively engageable with said dogs foroperating said rock shafts, a valve, a source of fluid pressurecommunicating therewith, conduits leading from said valve communicatingwith the opposite ends of said cylinder, an exhaust conduitcommunicating with said valve and means responsive to the pressure insaid boiler for operating said Valve to put either end of said cylinderinto communication with the source of fluid pressure and the opposite.end into communication with said exhaust conduit and a bleed passageleading from said valve to said boiler.

In testimony whereofI have hereunto set my hand in presence of twosubscribing wit nesses.

JOHN T. CULLEN, JR. Witnesses v THOMAS J. COLEMAN, JOHN T. GULLEN.

